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Peginterferon Alfa‐2a Does Not Alter the Pharmacokinetics of Methadone in Patients with Chronic Hepatitis C Undergoing Methadone Maintenance Therapy
Author(s) -
Sulkowski Mark,
Wright Teresa,
Rossi Stephen,
Arora Sanjeev,
Lamb Matthew,
Wang Ka,
Gries JeanMichel,
Yalamanchili Sreeni
Publication year - 2005
Publication title -
clinical pharmacology and therapeutics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.941
H-Index - 188
eISSN - 1532-6535
pISSN - 0009-9236
DOI - 10.1016/j.clpt.2004.09.008
Subject(s) - medicine , cmax , pharmacokinetics , methadone , regimen , methadone maintenance , pharmacodynamics , gastroenterology , hepatitis c , pharmacology
Objective Our objective was to quantify the pharmacokinetics of methadone and the pharmacokinetics and pharmacodynamics of peginterferon alfa‐2a (40 kd) in patients with chronic hepatitis C undergoing methadone maintenance therapy. Methods Adults with chronic hepatitis C who had been receiving a consistent methadone maintenance regimen for at least 3 months were eligible for this open‐label, multicenter, nonrandomized drug interaction study. All patients received 180 Μg subcutaneous peginterferon alfa‐2a once weekly for 4 weeks and continued their methadone regimen. Serial blood samples were collected at baseline and immediately before and for up to 168 hours after study drug administration for the purposes of quantifying methadone and peginterferon alfa‐2a serum concentrations, measuring serum 2′,5′‐oligoadenylate synthetase activity, and determining hepatitis C virus ribonucleic acid levels. Results Twenty‐four patients were enrolled. Methadone exposure, as measured by maximum serum concentration (C max ) and area under the concentration‐time curve (AUC) normalized to a 100‐mg/d dose, after 4 doses of peginterferon alfa‐2a increased by 10% to 15% when compared with baseline. The week 4/baseline ratio of the mean C max was 1.11 (90% confidence interval [CI], 1.02–1.22), and for AUC from time 0 to 24 hours, the week 4/baseline ratio was 1.15 (90% CI, 1.08–1.23). The mean accumulation ratios (week 4/first dose) for C max and AUC from time 0 to 168 hours of peginterferon alfa‐2a were 2.1 and 2.3, respectively. Conclusions Peginterferon alfa‐2a does not appreciably alter the pharmacokinetics of methadone. Clinical Pharmacology & Therapeutics (2005) 77 , 214–224; doi: 10.1016/j.clpt.2004.09.008